Language switching with slide gesture on spacebar. Bug: 2331173

Shows the language on the spacebar and in the preview bubble. Allows
dragging of the spacebar from side to side to switch to previous or
next languages.

1 files changed, 165 insertions, 0 deletions

diff --git a/src/com/android/inputmethod/latin/LanguageSwitcher.java b/src/com/android/inputmethod/latin/LanguageSwitcher.java
new file mode 100644
index 000000000..97173533d
--- /dev/null
+++ b/src/com/android/inputmethod/latin/LanguageSwitcher.java
@@ -0,0 +1,165 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package com.android.inputmethod.latin;
+
+import java.util.Locale;
+
+import android.content.SharedPreferences;
+import android.content.SharedPreferences.Editor;
+import android.preference.PreferenceManager;
+
+/**
+ * Keeps track of list of selected input languages and the current
+ * input language that the user has selected.
+ */
+public class LanguageSwitcher {
+
+    private Locale[] mLocales;
+    private LatinIME mIme;
+    private String[] mSelectedLanguageArray;
+    private String   mSelectedLanguages;
+    private int      mCurrentIndex = 0;
+    private String   mDefaultInputLanguage;
+    private Locale   mDefaultInputLocale;
+
+    public LanguageSwitcher(LatinIME ime) {
+        mIme = ime;
+        mLocales = new Locale[0];
+    }
+
+    public Locale[]  getLocales() {
+        return mLocales;
+    }
+
+    public int getLocaleCount() {
+        return mLocales.length;
+    }
+
+    /**
+     * Loads the currently selected input languages from shared preferences.
+     * @param sp
+     * @return whether there was any change
+     */
+    public boolean loadLocales(SharedPreferences sp) {
+        String selectedLanguages = sp.getString(LatinIME.PREF_SELECTED_LANGUAGES, null);
+        String currentLanguage   = sp.getString(LatinIME.PREF_INPUT_LANGUAGE, null);
+        if (selectedLanguages == null || selectedLanguages.length() < 1) {
+            loadDefaults();
+            if (mLocales.length == 0) {
+                return false;
+            }
+            mLocales = new Locale[0];
+            return true;
+        }
+        if (selectedLanguages.equals(mSelectedLanguages)) {
+            return false;
+        }
+        mSelectedLanguageArray = selectedLanguages.split(",");
+        mSelectedLanguages = selectedLanguages; // Cache it for comparison later
+        constructLocales();
+        mCurrentIndex = 0;
+        if (currentLanguage != null) {
+            // Find the index
+            mCurrentIndex = 0;
+            for (int i = 0; i < mLocales.length; i++) {
+                if (mSelectedLanguageArray[i].equals(currentLanguage)) {
+                    mCurrentIndex = i;
+                    break;
+                }
+            }
+            // If we didn't find the index, use the first one
+        }
+        return true;
+    }
+
+    private void loadDefaults() {
+        mDefaultInputLocale = mIme.getResources().getConfiguration().locale;
+        mDefaultInputLanguage = mDefaultInputLocale.getLanguage() + "_"
+                + mDefaultInputLocale.getCountry();
+    }
+
+    private void constructLocales() {
+        mLocales = new Locale[mSelectedLanguageArray.length];
+        for (int i = 0; i < mLocales.length; i++) {
+            mLocales[i] = new Locale(mSelectedLanguageArray[i]);
+        }
+    }
+
+    /**
+     * Returns the currently selected input language code, or the display language code if
+     * no specific locale was selected for input.
+     */
+    public String getInputLanguage() {
+        if (getLocaleCount() == 0) return mDefaultInputLanguage;
+
+        return mSelectedLanguageArray[mCurrentIndex];
+    }
+
+    /**
+     * Returns the currently selected input locale, or the display locale if no specific
+     * locale was selected for input.
+     * @return
+     */
+    public Locale getInputLocale() {
+        if (getLocaleCount() == 0) return mDefaultInputLocale;
+
+        return mLocales[mCurrentIndex];
+    }
+
+    /**
+     * Returns the next input locale in the list. Wraps around to the beginning of the
+     * list if we're at the end of the list.
+     * @return
+     */
+    public Locale getNextInputLocale() {
+        if (getLocaleCount() == 0) return mDefaultInputLocale;
+
+        return mLocales[(mCurrentIndex + 1) % mLocales.length];
+    }
+
+    /**
+     * Returns the previous input locale in the list. Wraps around to the end of the
+     * list if we're at the beginning of the list.
+     * @return
+     */
+    public Locale getPrevInputLocale() {
+        if (getLocaleCount() == 0) return mDefaultInputLocale;
+
+        return mLocales[(mCurrentIndex - 1 + mLocales.length) % mLocales.length];
+    }
+
+    public void reset() {
+        mCurrentIndex = 0;
+    }
+
+    public void next() {
+        mCurrentIndex++;
+        if (mCurrentIndex >= mLocales.length) mCurrentIndex = 0; // Wrap around
+    }
+
+    public void prev() {
+        mCurrentIndex--;
+        if (mCurrentIndex < 0) mCurrentIndex = mLocales.length - 1; // Wrap around
+    }
+
+    public void persist() {
+        SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(mIme);
+        Editor editor = sp.edit();
+        editor.putString(LatinIME.PREF_INPUT_LANGUAGE, getInputLanguage());
+        editor.commit();
+    }
+}